Method And Device For Controlling A Virtual Reality Graphic System Using Interactive Techniques
The invention relates to a method and a device for controlling a virtual reality (VR) graphic system using interactive techniques. Said VR graphic system comprises a projection device for visualising virtual three-dimensional scenes and the interaction with the VR graphic system takes place using at least one interactive device, which detects the respective position and/or orientation of the interactive device on a physical spatial trajectory, generates corresponding positional data and transmits said data to a position recorder of the VR graphic system. The invention is characterised in that an initial spatial point is defined on the physical spatial trajectory of the interactive device and that at least one subsequent interaction is evaluated in relation to the defined initial spatial point
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The present invention generally relates to graphics systems for virtual reality (VR) applications and specifically relates to a method and an apparatus for controlling such a VR graphics system using interactions as claimed in the preambles of the respective independent claims.
A VR graphics system which is concerned in this case is evident from DE 101 25 075 A1, for example, and is used to generate and display a multiplicity of three-dimensional views which together represent a virtual three-dimensional scene. In this case, such a scene is usually correspondingly visualized using stereoscopic projection onto a screen or the like. So-called immersive VR systems which form an intuitive man-machine (user) interface for the various areas of use (
As a result of the fact that three-dimensional data or objects are displayed to scale and as a result of the likewise three-dimensional ability to interact, these data or objects can be assessed and experienced far better than is possible with standard visualization and interaction techniques, for example with a 2D monitor and a correspondingly two-dimensional graphical user interface. A large number of physical real models and prototypes may thus be replaced with virtual prototypes in product development. A similar situation applies to planning tasks in the field of architecture, for example. Function prototypes may also be evaluated in a considerably more realistic manner in immersive environments than is possible with the standard methods.
Such a VR simulation is controlled in a computer-aided manner using suitable input units (referred to below, for the purpose of generalization, as “interaction units” since their function goes beyond pure data input) which, in addition to pushbuttons, have a position sensor which can be used to likewise continuously measure the spatial position and orientation of the interaction unit in order to carry out the interactions with the data which are displayed in the form of a scene (scene data). Such an interaction unit and a corresponding three-dimensional user interface are disclosed, for example, in DE 101 32 243 A1. The handheld cableless interaction unit described there is used to generate and transmit location, position and/or movement data (i.e. spatial position coordinates of the interaction unit) for the purpose of three-dimensional virtual navigation in said scene and in any functional elements of the user interface and for the purpose of manipulating virtual objects in the scene. To this end, the interaction unit has a sensor which interacts, via a radio connection, with a position detection sensor system provided in the VR graphics system. Said position data comprise the six possible degrees of freedom of translation and rotation of the interaction unit and are evaluated in real time in a computer-aided manner in order to determine a movement or spatial trajectory of the interaction unit.
User-guided interactions may, in principle, be subdivided into a logical part and a physical part. The logical part is the virtual three-dimensional user interface and includes, for example, the display of functions or menus, the method of selecting objects or function modes and the type of navigation. The physical part corresponds to the equipment-related implementation such as the technical configuration of the interaction unit and the projection technology used to display the scene.
As regards the use of said interaction units, it is desirable for said interactions, in particular more complex interactions such as function selection or menu control, to be as technically simple as possible and nevertheless to be capable of being controlled in a manner which is as safe as possible to use and is as operationally reliable as possible.
The invention therefore proposes a method and an apparatus for controlling a virtual reality (VR) graphics system (which is concerned in this case) using said interactions, which method and apparatus are based on the inventive concept of first of all forming a reference system, which is arranged on the spatial or movement trajectory of the interaction unit, and evaluating subsequent interactions using this reference system.
The special feature of the inventive method therefore resides in the fact that, as a result of a first interaction by the user, an initial spatial point which is initially fixed is determined, preferably together with an associated reference coordinate system, on the spatial trajectory of the interaction unit, and that the interaction unit is used to evaluate at least one subsequent interaction relative to the initial spatial point determined and the associated reference coordinate system.
Another refinement provides for the initial spatial point to represent the zero point or origin of said reference coordinate system and for reference or threshold values to be prescribed in this coordinate system, a particular function or a particular menu selection associated with the virtual user interface, which has been inserted into the current scene, being effected when said reference or threshold values are exceeded by the instantaneous spatial position or spatial orientation of the interaction unit. These reference values are preferably located on the surface of a geometric body which is arranged symmetrically (imaginary) with respect to the initial spatial point, for example on the surface of a sphere, the surface of an ellipsoid, the surface of a cube, the surface of a cuboid, the surface of a tetrahedron or the like. The reference points may also be weighted in particular spatial directions in order to assign different sensitivities to particular functions or menu selection items, during three-dimensional interaction, along the real spatial trajectory of the interaction unit, as a result of which incorrect operation or incorrect inputs by a user are avoided even more effectively.
Another refinement provides at least one further threshold value whose magnitude is greater than said at least one reference value, the reference coordinate system and the initial spatial point being caused to move to the new spatial position when said further threshold value is exceeded by the instantaneous spatial position of the interaction unit. This has the advantage that said advantageous method of operation of the reference coordinate system during said function or menu selection remains even in the case of (inadvertently) excessive changes in the position of the interaction unit.
The procedure proposed according to the invention and the user interface which is likewise proposed afford the advantage, in particular, that even complex interactions, for example over a plurality of function or menu levels, can be effected very intuitively, to be precise solely by means of spatial movement of the interaction unit. Only the determination of the first initial spatial point must be effected by means of a special interaction, preferably by means of a control element which is arranged on the interaction unit, for example a pushbutton or the like. In addition, control of the user interface by continuously evaluating said trajectory of the interaction unit becomes easier to handle and even more operationally reliable in comparison with the interaction systems which are known in the prior art.
Control of the VR graphics system using the interaction unit and a user interface that is visually inserted into the respective scene is preferably effected either via a function selection that is displayed in a three-dimensional visual manner or via a menu system such as the spherical menu described, for example, in DE 101 32 243 A1.
The invention can be used, with said advantages, in cableless and cable-bound interaction units which are preferably hand-guided by the user. It should be emphasized that, in addition to said use of the interaction unit including said control element (pushbutton), the possible interactions may also take place by means of acoustic or optical interactions, for example by means of voice, gestures or the like. In this case, use may be made of the input methods described in detail in the dissertation by A. RöBler entitled “Ein System für die Entwicklung von räumlichen Benutzungsschnittstellen” [A system for developing three-dimensional user interfaces], University of Stuttgart, published by Jost Jetter Verlag, Heimsheim, particularly on pages 72 ff. (chapters 4.3.2 ff.) thereof. In addition to the use of said interaction unit, the interaction modes described there such as direct and indirect and absolute and relative input may thus be additionally used to enable, for example, event-oriented interpretation of movements of the interaction unit or a part of the user's body.
In the case of said interpretation of the user's gestures, it is also possible to distinguish between static and dynamic gestures, the temporal sequence of a movement being analyzed in the case of dynamic gestures and a relative position or orientation between individual parts of the user's body, for example, being analyzed in the case of static gestures. In addition, it is possible to distinguish between simple input events and interpreted and combined input events, simple input events being triggered by discrete actions by the user, for example the operation of said pushbutton, whereas interpreted events are dynamically interpreted, for example taking into consideration a time measurement, for example when a button is pressed twice (“double click”). These two input modes may finally be combined in any desired manner, for example pressing a button once with a hand, head or facial gesture.
The inventive method and the apparatus are described below with reference to exemplary embodiments which are illustrated in the drawing and which reveal further features and advantages of the invention. In said exemplary embodiments, identical or functionally identical features are referenced using corresponding reference symbols.
IN THE DRAWING
The VR graphics system which is diagrammatically illustrated in
The user 105 holds an interaction unit 125 in his hand in order to generate preferably absolute position data such as the spatial position and orientation of the interaction unit in the physical space and to transmit said data to a position detection sensor system 130-140. Alternatively, however, relative or differential position data may also be used but this is not important in the present context.
The interaction unit 125 comprises a position detection system 145, preferably an arrangement of optical measurement systems 145, both the absolute values of the three possible angles of rotation and the absolute values of the translational movements of the interaction unit 125, which are possible in the three possible spatial directions, being detected using said arrangement of measurement systems and being processed in real time by a digital computer 150 in the manner described below. Alternatively, these position data may be detected using acceleration sensors, gyroscopes or the like which then generally provide only relative or differential position data. Since this sensor system is not important in the present case, a more detailed description is dispensed with here and reference is made to the documents mentioned at the outset.
Said absolute position data are generated by a computer system which is connected to the interaction unit 125. To this end, they are transmitted to a microprocessor 160 of a digital computer 150 in which, inter alia, the necessary graphical evaluation processes (which are to be assumed to be familiar to a person skilled in the art) are carried out in order to generate the stereoscopic three-dimensional scene 115. The three-dimensional scene representation 115 is used, in particular, for visualizing object manipulations, for three-dimensional navigation in the entire scene and for displaying function selection structures and/or menu structures.
In the present exemplary embodiment, the interaction unit 125 is connected, for carrying data, to the digital computer 150, via a radio connection 170, using a reception part 165 (which is arranged there). The position data which are transmitted from the sensors 145 to the position detection sensor system 130-140 are likewise transmitted in a wireless manner by radio links 175-185.
Additionally depicted are the head position (HP) of the user 105 and his viewing direction (VD) 190 with respect to the projection screen 100 and the scene 115 projected there. These two variables are important for calculating a current stereoscopic projection insofar as they considerably concomitantly determine the necessary scene perspective since the perspective also depends, in a manner known per se, on these two variables.
In the present exemplary embodiment, the interaction unit 125 comprises a pushbutton 195 which the user 105 can use, in addition to said possibilities for moving the interaction unit 125 in the space, to mechanically trigger an interaction, as described below with reference to
The central element of the immersive VR graphics system shown is the stereoscopic representation (which is guided (tracked) using the position detection sensor system 130-140) of the respective three-dimensional scene data 115. In this case, the perspective of the scene representation depends on the observer's vantage point and on the head position (HP) and viewing direction (VD). To this end, the head position (HP) is continuously measured using a three-dimensional position measurement system (not illustrated here) and the geometry of the view volumes for both eyes is adapted according to these position values. This position measurement system comprises a similar sensor system to said position detection system 130-140 and may be integrated in the latter, if appropriate. A separate image from the respective perspective is calculated for each eye. The difference (disparity) gives rise to the stereoscopic perception of depth.
In the present case, an interaction by a user is understood as meaning any action by the user, preferably using said interaction unit 125. Included in this case are the movement of the interaction unit 125 on a spatial trajectory shown in
At the same time as the reference coordinate system 210 is determined, two shells which are arranged around the ISP 205 are calculated, to be precise an inner shell 215 having corresponding shell segments 217 and a continuous (i.e. not subdivided into such shell segments) outer shell 220. It should be emphasized that, in the technical sense, the shells shown represent only auxiliary means when calculating said threshold values and when calculating or detecting when these threshold values have been exceeded by the spatial trajectory of the interaction unit 125 and these shells therefore do not visually appear in the scene. The inner shell 215 defines the first threshold value mentioned at the outset, whereas the outer shell represents said second threshold value.
When penetrated by the trajectory 200, said shell segments 217 of the inner shell 215 are used to automatically trigger actions, preferably in a menu system of a user interface that is visualized in the present scene, to be precise actions such as opening a new menu item or selecting a function or a function mode from a multiplicity of functions or function modes offered. All known and conceivable manifestations, for example sphere-based or ellipsoid-based menus, cube-based or cuboid-based menus or flat transparent text menus, are suitable, in principle, as the menu system. The precise method of operation of such menu systems for selecting function modes or the like is described in detail in the two documents mentioned at the outset and these documents are therefore referred to in full in this respect in the present context.
The course of the trajectory shown in
For reasons of symmetry (spherical symmetry of the above-described shells), the present exemplary embodiment is likewise preferably a spherical symmetrical menu system, for example a spherical menu. It goes without saying that the spherical shells shown in
The trajectory 200 shown in
It goes without saying that, in the simplest refinement, the threshold value areas shown in
In an alternative refinement, the ISP follows the trajectory incrementally (i.e. in incremental steps or virtually gradually), either the outer shell being degenerated to a shell with a smaller diameter than the inner shell or the ISP respectively following the continuing trajectory incrementally as of said penetration point 225. As already said, the outer shell does not have any segmentation since it is not intended to trigger any use-specific events but merely said correction of the entire reference coordinate system 210.
It should be noted that, for the purpose of generalization, the physical spatial trajectory shown in
If such an initial interaction is determined, said reference coordinate system 210 is first of all determined in step 310, the coordinate origin being formed by the ISP 205. In subsequent steps 315 and 320, the reference points or reference area segments 217 of said first threshold 215 and the second threshold area 220 are determined in the reference coordinate system 210.
Said steps are again followed by a loop in which the current position of the interaction unit 125 is first of all detected 325. A check is then carried out 330 in order to determine whether the detected value of the current position is outside said first threshold value or the value of the present reference area segment 217. If this condition 330 is not satisfied, the routine jumps back to step 325 in order to detect a new current position value of the interaction unit 125. However, if the condition 330 is satisfied, the trajectory has penetrated the first threshold area 215. In this case, a check is also first of all carried out 335 in order to determine which reference point or which reference area segment in the reference coordinate system is affected thereby. The corresponding function or menu selection is then triggered 340 on the basis of the result of the last check 335.
In the special case of the triggered function being a function that ends the entire routine, which is additionally checked in step 342, the process jumps to step 343 in which the routine is then ended.
In the case of the trajectory actually having penetrated the first threshold area 215, a check is also carried out 345 in order to determine whether the trajectory has also already penetrated the second threshold area 220. That is to say a check is also carried out 345 in this case in order to determine whether the magnitude of the value of the current position of the interaction unit 125 in the present reference coordinates exceeds the value of the second threshold. If this condition is not satisfied, the process jumps back to step 325 again and a new position value of the interaction unit 125 is detected. Otherwise, the reference coordinate system and its origin 350 which coincides with the ISP 205 are corrected and, if appropriate, incrementally shifted to the current position of the trajectory of the interaction unit 125.
It should finally be noted that the above-described concept of the initial spatial point (ISP) also includes, in principle, user interfaces in which the interaction is effected using a pure rotation of the interaction unit 125 or a combination of a pure translation and a pure rotation. In the case of a rotation, the ISP can be understood as meaning an initial spatial angle φ=0° of an imaginary spherical or cylindrical coordinate system. In this case, the two threshold values described may be formed by discrete angles, for example φ=90° and φ=180°, said coordinate system then being corrected, for example, by the angle φ=180° when the threshold values are exceeded by φ=180°.
Claims
1. A method for controlling a virtual reality (VR) graphics system using interactions, the VR graphics system having a projection device for visualizing virtual three-dimensional scenes and the interactions with the VR graphics system taking place using at least one interaction unit, which is used to detect the respective position and/or orientation of the interaction unit on a physical spatial trajectory and to generate corresponding position data and to transmit these position data to a position detection device of the VR graphics system, characterized in that an initial spatial point on the physical spatial trajectory of the interaction unit is determined, and in that at least one subsequent interaction is evaluated relative to the initial spatial point determined.
2. The method as claimed in claim 1, characterized in that reference coordinates are determined using the initial spatial point, the at least one subsequent interaction being evaluated relative to these reference coordinates.
3-16. (canceled)
17. The method as claimed in claim 1, characterized in that at least one threshold value or a first threshold value area is formed using the initial spatial point and/or the reference coordinates, at least one action or function of the VR graphics system being triggered when said threshold value or threshold value area is exceeded by the physical spatial trajectory.
18. The method as claimed in claim 17, characterized in that the first threshold value area defines at least two different threshold values which are used for weighting when the at least one action or function of the VR graphics system is triggered.
19. The method as claimed in claim 17, characterized in that the first threshold value area is formed by a symmetrical three-dimensional body, in particular a sphere, an ellipsoid, a cube, a cuboid or the like.
20. The method as claimed in claim 1, characterized in that the initial spatial point and/or the reference coordinates is/are used to form at least one second threshold value area whose value is essentially greater than the value of the first threshold value area, shifting of the zero point of the reference coordinates in the direction of the spatial trajectory being triggered when said second threshold value area is exceeded by the physical spatial trajectory.
21. The method as claimed in claim 1, characterized in that the initial spatial point is determined using a first interaction.
22. The method as claimed in claim 21, characterized in that the first interaction takes place using the interaction unit, in particular using a control element which is arranged on the interaction unit, or using a user's acoustic, linguistic or gesticulatory interaction.
23. The method as claimed in claim 1 for use in a VR graphics system having at least one three-dimensional virtual menu system or function selection system, characterized in that the at least one subsequent interaction is used to control the menu system or the function selection system.
24. The method as claimed in claim 23, characterized in that, on account of the first interaction, the menu system or the function selection system is inserted into the virtual scene, with regard to the projection device, on the basis of the viewing direction and/or the head position of a user who is holding the interaction unit, in that the viewing direction and/or the head position is/are detected continuously or occasionally, and in that the position on the projection device, at which the menu system or the function selection system is/are inserted, is determined on the basis of the viewing direction detected and/or the head position detected.
25. The method as claimed in claim 23, characterized in that an action or function which is to be effected by means of a rotational movement of the interaction unit is triggered only when at least one second interaction is carried out, in particular using the control element.
26. A three-dimensional user interface for controlling a virtual reality (VR) graphics system using interactions, the VR graphics system having a projection device for visualizing virtual three-dimensional scenes and the interactions with the VR graphics system taking place using at least one interaction unit, which is used to detect the respective position and/or orientation of the interaction unit on a physical spatial trajectory and to generate corresponding position data and to transmit these position data to a position detection device of the VR graphics system, characterized by means for generating an initial spatial point on the physical spatial trajectory of the interaction unit and for evaluating at least one subsequent interaction relative to the initial spatial point determined.
27. The user interface as claimed in claim 26, characterized by means for calculating virtual reference coordinates on the basis of the initial spatial point and for evaluating the at least one subsequent interaction relative to these reference coordinates.
28. The user interface as claimed in claim 27, characterized by means for calculating at least one threshold value or a first threshold value area on the basis of the reference coordinates and means for triggering an action or function of the VR graphics system when the threshold value or the first threshold value area is exceeded by the physical spatial trajectory.
29. The user interface as claimed in claim 26, characterized by means for calculating at least one second threshold value area on the basis of the reference coordinates, the value of said second threshold value area essentially greater than the value of the first threshold value area, and means for shifting the zero point of the reference coordinates in the direction of the spatial trajectory when the second threshold value area is exceeded by the physical spatial trajectory.
30. A virtual reality (VR) graphics system which operates according to the method of claim 1.
31. A virtual reality (VR) graphics system which has a user interface as claimed in claim 26.
Type: Application
Filed: Sep 16, 2004
Publication Date: Aug 30, 2007
Applicant: ICIDO GESELLSCHAFT FUR INNOVATIVE INFORMATIONSSYST (Stuttgart)
Inventors: Andreas Rossler (Stuttgart), Ralf Breining (Ostfildern), Jan Wurster (Stuttgart)
Application Number: 10/595,182
International Classification: G06T 15/00 (20060101);